Kodaira Megumi is a normal 17-year-old girl who attends a public high school in Tokyo. No matter how hard she tries, she just can't study, and people around her say she's unmotivated. In fact, her IQ is 76. Although she does not have an intellectual disability (IQ less than 70), she falls under "borderline intelligence", which is below average. People with borderline intelligence are said to make up 14% of the population, which equates to 5 people in a class of 35 people. Megumi has been left behind by society as she is forced to compete in the same arena as people of average intelligence. Then, due to a certain mistake, a child becomes pregnant and a tragedy occurs.